The prevalence of schistosomiasis in Uganda: A nationally representative population estimate to inform control programs and water and sanitation interventions

A comprehensive exploration of schistosomiasis: Global impact, molecular characterization, drug discovery, artificial intelligence and future prospects

Schistosomiasis, one of the neglected tropical diseases which affects both humans and animals, is caused by trematode worms of the genus Schistosoma. The disease is caused by several species of Schistosoma which affect several organs such as urethra, liver, bladder, intestines, skin and bile ducts. The life cycle of the disease involves an intermediate host (snail) and a mammalian host. It affects people who are in close proximity to water bodies where the intermediate host is abundant. Common clinical manifestations of the disease at various stages include fever, chills, headache, cough, dysuria, hyperplasia and hydronephrosis. To date, most of the control strategies are dependent on effective diagnosis, chemotherapy and public health education on the biology of the vectors and parasites. Microscopy (Kato-Katz) is considered the golden standard for the detection of the parasite, while praziquantel is the drug of choice for the mass treatment of the disease since no vaccines have yet been developed. Most of the previous reviews on schistosomiasis have concentrated on epidemiology, life cycle, diagnosis, control and treatment. Thus, a comprehensive review that is in tune with modern developments is needed. Here, we extend this domain to cover historical perspectives, global impact, symptoms and detection, biochemical and molecular characterization, gene therapy, current drugs and vaccine status. We also discuss the prospects of using plants as potential and alternative sources of novel anti-schistosomal agents. Furthermore, we highlight advanced molecular techniques, imaging and artificial intelligence that may be useful in the future detection and treatment of the disease. Overall, the proper detection of schistosomiasis using state-of-the-art tools and techniques, as well as development of vaccines or new anti-schistosomal drugs may aid in the elimination of the disease.

Factors associated with hookworm and Schistosoma mansoni infections among school-aged children in Mayuge district, Uganda

BACKGROUND

Hookworm infection and schistosomiasis are two of sub-Saharan Africa's most common neglected tropical diseases. An annual mass drug administration (MDA) program against schistosomiasis and soil-transmitted helminths (STHs), including hookworm, has been implemented in Mayuge district, Uganda, since 2003 to date. However, hookworm and schistosomiasis remain prevalent in Mayuge district. Understanding the factors that predispose children to these infections in the context of MDA could inform interventions to reduce prevalence in Uganda and similar settings.

METHOD

This cross-sectional study took place in 33 randomly selected primary schools in the Mayuge district from January to February 2022. Children in primary classes 4 or 5, in the selected schools provided single stool samples and completed questionnaires. Stool specimens were examined using the Kato-Katz method to determine the prevalence of hookworm and schistosomiasis. We performed univariable and multivariable logistic regression to assess the associations of each infection with potential risk factors.

RESULT

A total of 1,617 students (mean age 12.1 years, 50.1% male) were enrolled. The prevalence of hookworm infection and schistosomiasis was 21.8% (95% confidence interval (CI): 19.8-23.9%) and 18.7% (95% CI: 16.8-20.7%), respectively. In multivariable analysis, longer water fetching time (over 30 min versus less than 30 min) and working daily in the soil were associated with increased odds of hookworm infection (adjusted odds ratio (AOR): 1.49, 95% CI: 1.13-1.96 and 1.37, 95% CI: 1.03-1.82, respectively). Higher odds of schistosomiasis were linked to proximity to water bodies within a one-hour walking distance (AOR: 1.84, 95% CI: 1.35-2.50), and not always washing hands before eating (AOR: 2.00, 95% CI: 1.50-2.67). Swimming, bathing, or washing in water bodies twice a week, compared to never, also increased schistosomiasis odds (AOR: 2.91, 95% CI: 1.66-5.13).

CONCLUSION

Consistent with the mechanisms of acquisition, hookworm infection increased with exposure to soil, and schistosomiasis increased with exposure to unclean water. Our findings highlight the importance of Water, Sanitation, and Hygiene programs and strategies aimed at reducing exposure within the framework of Neglected Tropical Disease elimination programs.

The short-term impact of Schistosoma mansoni infection on health-related quality of life: implications for current elimination policies

The WHO aims to eliminate schistosomiasis as a public health problem by 2030. However, standard morbidity measures poorly correlate to infection intensities, hindering disease monitoring and evaluation. This is exacerbated by insufficient evidence on Schistosoma's impact on health-related quality of life (HRQoL). We conducted community-based cross-sectional surveys and parasitological examinations in moderate-to-high Schistosoma mansoni endemic communities in Uganda. We calculated parasitic infections and used EQ-5D instruments to estimate and compare HRQoL utilities in these populations. We further employed Tobit/linear regression models to predict HRQoL determinants. Two-thirds of the 560 participants were diagnosed with parasitic infection(s), 49% having S. mansoni. No significant negative association was observed between HRQoL and S. mansoni infection status/intensity. However, severity of pain urinating (β = -0.106; s.e. = 0.043) and body swelling (β = -0.326; s.e. = 0.005), increasing age (β = -0.016; s.e. = 0.033), reduced socio-economic status (β = 0.128; s.e. = 0.032), and being unemployed predicted lower HRQoL. Symptom severity and socio-economic status were better predictors of short-term HRQoL than current S. mansoni infection status/intensity. This is key to disentangling the link between infection(s) and short-term health outcomes, and highlights the complexity of correlating current infection(s) with long-term morbidity. Further evidence is needed on long-term schistosomiasis-associated HRQoL, health and economic outcomes to inform the case for upfront investments in schistosomiasis interventions.

Assessing the knowledge, training and capacity of health workers in the diagnosis and management of soil-transmitted helminths and schistosomiasis in eastern Uganda

BACKGROUND

Neglected tropical diseases (NTDs) affect millions of people in Africa, with Uganda bearing a significant burden. The World Health Organization (WHO) set a goal to reduce NTDs and improve access to diagnosis and management by 2030. However, NTDs have not been well integrated into primary healthcare in many countries, including Uganda, due to limited knowledge and resources among health workers. The study aimed to assess the readiness and capacity of primary healthcare centres to diagnose and manage soil-transmitted helminths (STHs) and schistosomiasis.

METHODS

A cross-sectional quantitative study was conducted among 204 health workers in 20 health facilities in four districts bordering Lake Kyoga. In this study we evaluated health workers' knowledge of symptoms, diagnosis and management of STHs and schistosomiasis as well as the availability of resources and training.

RESULTS

Our findings indicate that health workers have strong knowledge about STHs (86.76%), with lower knowledge levels regarding Schistosoma haematobium (59.72%) and Schistosoma mansoni (71.43%). Regarding resources and training, 95% of health facilities had laboratory services, but the majority lacked diagnostic equipment. Furthermore, only 17% of health workers reported prior training on schistosomiasis and related topics and only 25% had training on surveillance and reporting.

CONCLUSIONS

While health workers in eastern Uganda demonstrated a good knowledge base for some NTDs, there were knowledge gaps and challenges in training on surveillance and reporting mechanisms. Continuously building the capacity of health workers along with investing in diagnostic infrastructure is essential for improved NTD control and ultimately reducing associated morbidity and mortality in the region.

Helminth exposure and immune response to the two-dose heterologous Ad26.ZEBOV, MVA-BN-Filo Ebola vaccine regimen

BACKGROUND

The exposure to parasites may influence the immune response to vaccines in endemic African countries. In this study, we aimed to assess the association between helminth exposure to the most prevalent parasitic infections, schistosomiasis, soil transmitted helminths infection and filariasis, and the Ebola virus glycoprotein (EBOV GP) antibody concentration in response to vaccination with the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen in African and European participants using samples obtained from three international clinical trials.

METHODS/PRINCIPAL FINDINGS

We conducted a study in a subset of participants in the EBL2001, EBL2002 and EBL3001 clinical trials that evaluated the Ad26.ZEBOV, MVA-BN-Filo vaccine regimen against EVD in children, adolescents and adults from the United Kingdom, France, Burkina Faso, Cote d'Ivoire, Kenya, Uganda and Sierra Leone. Immune markers of helminth exposure at baseline were evaluated by ELISA with three commercial kits which detect IgG antibodies against schistosome, filarial and Strongyloides antigens. Luminex technology was used to measure inflammatory and activation markers, and Th1/Th2/Th17 cytokines at baseline. The association between binding IgG antibodies specific to EBOV GP (measured on day 21 post-dose 2 and on Day 365 after the first dose respectively), and helminth exposure at baseline was evaluated using a multivariable linear regression model adjusted for age and study group. Seventy-eight (21.3%) of the 367 participants included in the study had at least one helminth positive ELISA test at baseline, with differences of prevalence between studies and an increased prevalence with age. The most frequently detected antibodies were those to Schistosoma mansoni (10.9%), followed by Acanthocheilonema viteae (9%) and then Strongyloides ratti (7.9%). Among the 41 immunological analytes tested, five were significantly (p < .003) lower in participants with at least one positive helminth ELISA test result: CCL2/MCP1, FGFbasic, IL-7, IL-13 and CCL11/Eotaxin compared to participants with negative helminth ELISA tests. No significant association was found with EBOV-GP specific antibody concentration at 21 days post-dose 2, or at 365 days post-dose 1, adjusted for age group, study, and the presence of any helminth antibodies at baseline.

CONCLUSIONS/SIGNIFICANCE

No clear association was found between immune markers of helminth exposure as measured by ELISA and post-vaccination response to the Ebola Ad26.ZEBOV/ MVA-BN-Filo vaccine regimen.

TRIAL REGISTRATION

NCT02416453, NCT02564523, NCT02509494. ClinicalTrials.gov.

A cross-sectional pilot household study of Schistosoma mansoni burden and associated morbidities in Lake Albert, Uganda

OBJECTIVES

Schistosomiasis is persistent in Lake Albert, Uganda, but local data are limited. This study aims to describe the local burden of moderate-to-heavy infection and associated morbidity in all ages and identify factors associated with these outcomes to guide further research.

METHODS

This cross-sectional pilot study was conducted in July-August, 2022 in four village sites (Walukuba, Rwentale, Kyabarangwa and Runga) of the Praziquantel in Preschoolers (PIP) trial. Residents (approximately four per household) of any age of households of PIP participants were eligible, but individuals <10 years were only enrolled if no older individuals were available. Socio-demographic information, household location, single stool Kato-Katz and hepatic ultrasound results were obtained for a convenience sampled subset of trial households. The primary outcome, moderate-to-heavy infection (≥100 eggs per gram of faeces), was analysed using mixed-effects logistic regression, with a household random effect. Univariate analyses were used for the secondary outcome, periportal fibrosis (Niamey protocol ultrasound image pattern C-F).

RESULTS

Of 243 participants with a median age of 22 (interquartile range 12-33) years from 66 households, 49.8% (103/207 with a Kato-Katz result) had moderate-to-heavy infection and 11.2% (25/224 with ultrasound data) had periportal fibrosis. Moderate-to-heavy infection clustered by household (intraclass correlation coefficient = 0.11) and, in multivariable analysis, varied by village (Walukuba vs. Kyabarangwa adjusted odds ratio [aOR] 0.11, 95% CI 0.02-0.71), was highest in participants aged 10-15 years (vs. 5-9 years aOR 6.14, 95% CI 1.61-23.38) and lower in those reporting praziquantel treatment in the past year (aOR 0.39, 95% CI 0.18-0.88).

CONCLUSIONS

In this setting, schistosome infection and morbidity are pervasive in all age groups. More intensive interventions are needed, for example more frequent praziquantel treatment, under investigation in the PIP trial and improved water and sanitation. More research is needed to understand local treatment barriers and optimal control strategies.

An accident waiting to happen? Exposing the potential of urogenital schistosomiasis transmission in the Lake Albert region, Uganda

BACKGROUND

Urogenital schistosomiasis caused by the parasitic blood fluke Schistosoma haematobium is the most common form of that constitutes a majority of over 240 million schistosomiasis cases. The enigmatic absence of urogenital schistosomiasis in Uganda has, until now, been attributed to the absence of substantial populations of suitable snail intermediate hosts.

METHODS

Malacological surveys were carried out in 73 sites southeast of Lake Albert, Uganda in October and November 2020. Collected snails were transported to the laboratory for identification. The snails were identified using partial mitochondrial cytochrome c oxidase subunit one and nuclear internal transcribed spacer barcoding. Schistosome infections in snails were also assessed using cercarial shedding and rapid diagnostic PCR techniques.

RESULTS

We found Bulinus globosus and Bulinus nasutus productus, the main intermediate species in the transmission of S. haematobium in mainland East Africa. In this survey, B. globosus was more common than B. nasutus productus, with the former reported at four sites (total count = 188) and the latter reported at one site (total count = 79). Molecular testing revealed a high prevalence of Schistosoma bovis in B. nasutus productus (16%), but no S. haematobium infections were found.

CONCLUSIONS

Given the abundance of snail hosts and the risky human water contact behaviours observed, we highlight the potential for urogenital schistosomiasis transmission in the region.

Transcriptome analysis of peripheral blood of Schistosoma mansoni infected children from the Albert Nile region in Uganda reveals genes implicated in fibrosis pathology

Over 290 million people are infected by schistosomes worldwide. Schistosomiasis control efforts focus on mass drug treatment with praziquantel (PZQ), a drug that kills the adult worm of all Schistosoma species. Nonetheless, re-infections have continued to be detected in endemic areas with individuals living in the same area presenting with varying infection intensities. Our objective was to characterize the transcriptome profiles in peripheral blood of children between 10-15 years with varying intensities of Schistosoma mansoni infection living along the Albert Nile in Uganda. RNA extracted from peripheral blood collected from 44 S. mansoni infected (34 high and 10 low by circulating anodic antigen [CAA] level) and 20 uninfected children was sequenced using Illumina NovaSeq S4 and the reads aligned to the GRCh38 human genome. Differential gene expression analysis was done using DESeq2. Principal component analysis revealed clustering of gene expression by gender when S. mansoni infected children were compared with uninfected children. In addition, we identified 14 DEGs between S. mansoni infected and uninfected individuals, 56 DEGs between children with high infection intensity and uninfected individuals, 33 DEGs between those with high infection intensity and low infection intensity and no DEGs between those with low infection and uninfected individuals. We also observed upregulation and downregulation of some DEGs that are associated with fibrosis and its regulation. These data suggest expression of fibrosis associated genes as well as genes that regulate fibrosis in S. mansoni infection. The relatively few significant DEGS observed in children with schistosomiasis suggests that chronic S. mansoni infection is a stealth infection that does not stimulate a strong immune response.

Gendered lives, gendered Vulnerabilities: An intersectional gender analysis of exposure to and treatment of schistosomiasis in Pakwach district, Uganda

INTRODUCTION

Schistosomiasis is a neglected tropical disease (NTD) that is endemic in Uganda, despite several interventions to eliminate it. It is transmitted when people infected with it pass on their waste matter into fresh water bodies used by others, consequently infecting them. Several studies have demonstrated gender and age differences in prevalence of schistosomiasis and NTDs such as lymphatic filariasis and soil transmitted helminths. However, few intersectional gender analysis studies of schistosomiasis have been undertaken. Using the World Health Organisation (WHO)'s intersectional gender analysis toolkit, this study was undertaken to identify which social stratifiers most intersected with gender to influence vulnerability to and access to treatment for schistosomiasis disease, to understand how best to implement interventions against it.

METHODOLOGY

This was a qualitative study comprising eight focus group discussions (FGDs) of community members, disaggregated by age, sex and location, and 10 key informant interviews with health care providers and community leaders. The Key informants were selected purposively while the community members were selected using stratified random sampling (to cater for age, sex and location). The data was analysed manually to identity key themes around gender, guided by a gender and intersectionality lens.

RESULTS

The study established that while the River Nile provided livelihoods it also exposed the community to schistosomiasis infection. Gender relations played a significant role in exposure to and access to treatment for schistosomiasis. Traditional gender roles determined the activities men and women performed in the private and public spheres, which in turn determined their exposure to schistosomiasis and treatment seeking behaviour. Gender relations also affected access to treatment and decision making over family health care. Men and some women who worked outside the home were reported to prioritise their income earning activities over seeking health care, while women who visited the health facilities more regularly for antenatal care and to take sick children were reported to have higher chance of being tested and treated in time, although this was undermined by the irregular and infrequent provision of praziquantel (PZQ) mass drug administration. These gender relations were further compounded by underdevelopment and limited economic opportunities, insufficient health care services, as well as the respondent's age and location.

CONCLUSIONS

The study concludes that vulnerability to schistosomiasis disease and treatment occurred within a complex web of gender relations, culture, poverty, limited economic opportunities and insufficient health services delivery, which together undermined efforts to eliminate schistosomiasis. This study recommends the following: a) increased public health campaigns around schistosomiasis prevention and treatment; b) more regular PZQ MDA at home and schools; c) improved health services delivery and integration of services to include vector control; d) prioritising NTDs; e) providing alternative economic activities; and f) addressing negative gender norms that promote social behaviours which negatively influence vulnerability, treatment seeking and decision making for health.

Variants of IL6, IL10, FCN2, RNASE3, IL12B and IL17B loci are associated with Schistosoma mansoni worm burden in the Albert Nile region of Uganda

BACKGROUND

Individuals genetically susceptible to high schistosomiasis worm burden may contribute disproportionately to transmission and could be prioritized for control. Identifying genes involved may guide development of therapy.

METHODOLOGY/PRINCIPAL FINDINGS

A cohort of 606 children aged 10-15 years were recruited in the Albert Nile region of Uganda and assessed for Schistosoma mansoni worm burden using the Up-Converting Particle Lateral Flow (UCP-LF) test detecting circulating anodic antigen (CAA), point-of-care Circulating Cathodic Antigen (POC-CCA) and Kato-Katz tests. Whole genome genotyping was conducted on 326 children comprising the top and bottom 25% of worm burden. Linear models were fitted to identify variants associated with worm burden in preselected candidate genes. Expression quantitative trait locus (eQTL) analysis was conducted for candidate genes with UCP-LF worm burden included as a covariate. Single Nucleotide Polymorphism loci associated with UCP-LF CAA included IL6 rs2066992 (OR = 0.43, p = 0.0006) and rs7793163 (OR = 2.0, p = 0.0007); IL21 SNP kgp513476 (OR 1.79, p = 0.0025) and IL17B SNP kgp708159 (OR = 0.35, p = 0.0028). A haplotype in the IL10 locus was associated with lower worm burden (OR = 0.53, p = 0.015) and overlapped SNPs rs1800896, rs1800871 and rs1800872. Significant haplotypes (p<0.05, overlapping significant SNP) associated with worm burden were observed in IL6 and the Th17 pathway IL12B and IL17B genes. There were significant eQTL in the IL6, IL5, IL21, IL25 and IFNG regions.

CONCLUSIONS

Variants associated with S. mansoni worm burden were in IL6, FCN2, RNASE3, IL10, IL12B and IL17B gene loci. However only eQTL associations remained significant after Bonferroni correction. In summary, immune balance, pathogen recognition and Th17 pathways may play a role in modulating Schistosoma worm burden. Individuals carrying risk variants may be targeted first in allocation of control efforts to reduce the burden of schistosomiasis in the community.

Seasonal patterns of Schistosoma mansoni infection within Biomphalaria snails at the Ugandan shorelines of Lake Albert and Lake Victoria

Intestinal schistosomiasis is hyperendemic in many sub-Saharan African countries. In Uganda, it is endemic at both Lake Albert (LA) and Lake Victoria (LV) and caused by S. mansoni that uses Biomphalaria snails as obligatory intermediate snail hosts. To shed light on local patterns of infection, we utilised two PCR-based methods to detect S. mansoni within Biomphalaria spp. as collected at the Ugandan shorelines of Lake Albert and Lake Victoria from 2009-2010. Overall, at our Lake Albert sites, the mean infection prevalence was 12.5% (15 of 120 snails), while at our Lake Victoria sites the prevalence was 5% (3 of 60 snails). At our Lake Albert sites, the highest infection prevalence of 13.3% (8 of 60 snails) was at Walukuba, while at our Lake Victoria sites, the highest infection prevalence of 10% (2 of 20 snails) was at Lwanika. Three species of Biomphalaria, B. pfeifferi, B. stanleyi and B. sudanica, were identified at our Lake Albert collection sites, while only a single species, B. choanomphala, was identified at our Lake Victoria collection sites. Biomphalaria stanleyi (2 of 20 snails; 15%) had the highest infection prevalence, followed by B. sudanica (5 of 60 snails; 13.3%), B. pfeifferi (4 of 40 snails; 10%) and B. choanomphala (3 of 60 snails; 5%). Of the Biomphalaria species identified, B. choanomphala had the highest haplotype (gene) diversity score, followed by B. stanleyi, B. sudanica and B. pfeifferi. Sites with a higher mean prevalence of S. mansoni infection had higher intra-species haplotype diversity scores than sites with a lower mean prevalence. The wet seasons (LA: 13.3%; LV: 8.7%) had a consistently higher mean infection prevalence of S. mansoni than the dry seasons (LA: 9.5%; LV: 5%) for all species and all sites tested at both Lake Albert (n = 480) and Lake Victoria (n = 320), though the difference was not statistically significant.

The association between menstrual hygiene, workplace sanitation practices and self-reported urogenital symptoms in a cross-sectional survey of women working in Mukono District, Uganda

BACKGROUND

Women worldwide experience challenges managing their periods. Menstrual and genital hygiene behaviours have been linked to negative health outcomes, including urogenital symptoms and confirmed infections. However, evidence testing this association has been limited and mixed. This study aimed to (1) describe the menstrual care practices and prevalence of self-reported urogenital symptoms among working women in Mukono District, Uganda, and (2) test the associations between menstrual and genital care practices, and urogenital symptoms.

METHODOLOGY

We undertook a cross-sectional survey of women aged 18-45 working in markets, schools, and healthcare facilities in Mukono District, with 499 participants who had menstruated in the past two months included in this analysis. We developed an aggregated measure of menstrual material cleanliness, incorporating material type and laundering practices. Associations with urogenital symptoms were tested using the aggregated material cleanliness measure alongside the frequency of changing materials, handwashing before menstrual tasks, and sanitation practices.

RESULTS

Among our sample, 41% experienced urogenital symptoms in the past month. Compared to women exclusively using disposable pads, using appropriately cleaned or non-reused improvised materials (PR = 1.33, 95%CI 1.04-1.71), or inadequately cleaned materials (improvised or commercially produced reusable pads) (PR = 1.84, 95%CI 1.46-3.42) was associated with an increased prevalence of self-reported urogenital symptoms in the last month. There was no difference between those using disposable pads and those using clean reusable pads (PR = 0.98; 95%CI 0.66-1.57). Infrequent handwashing before changing materials (PR 1.18, 95%CI: 0.96-1.47), and delaying urination at work (PR = 1.37, 95%CI: 1.08-1.73) were associated with an increased prevalence of self-reported symptoms.

CONCLUSION

Prevalence of self-reported urogenital symptoms was associated with the type and cleanliness of menstrual material used as well as infrequent handwashing and urinary restriction. There is a need for interventions to enable women to maintain cleanliness of their menstrual materials and meet their menstruation, urination and hand washing needs at home and work.

Health-seeking behaviour regarding schistosomiasis treatment in the absence of a mass drug administration (MDA) program: the case of endemic communities along Lake Albert in Western Uganda

INTRODUCTION

Schistosomiasis poses a serious public health problem and a social challenge affecting over 240 million people, the majority of whom live in sub-Saharan Africa. The World Health Organization (WHO) recommends praziquantel (PZQ) drug treatment through regular mass drug administration (MDA) accompanied by social mobilisation and health education and sensitisation. With social mobilisation and health education and sensitisation, there is bound to be increased demand for the PZQ, especially in the case of endemic communities. However, it is not clear where communities go for PZQ treatment in the absence of PZQ MDA. We explored the health-seeking behaviours regarding schistosomiasis treatment among communities along Lake Albert in Western Uganda when MDA had delayed, to inform a review of the implementation policy for the achievement of the WHO's 2030 target of 75% coverage and uptake.

METHODS AND MATERIALS

We conducted a community-based qualitative study in Kagadi and Ntoroko, an endemic community in January and February 2020. We interviewed 12 individuals: local leaders, village health teams, and health workers, and conducted 28 focus group discussion sessions with 251 purposively selected community members. The audio recordings of the data were transcribed and analyzed using a thematic analysis model.

RESULTS

Generally, participants seldom seek medication for schistosomiasis-related signs and symptoms from government hospitals and health centres II, III and IV. Instead, they rely on community volunteers such as VHTs, private facilities, such as clinics and drug shops nearby, or traditional sources (e.g. witch doctors and herbalists). Results show that factors influencing people to seek treatment from sources other than the government are: the absence of PZQ drugs in the government health facility; health workers' negative attitude towards patients; long distances to the government hospitals and health facilities; poor and inaccessible roads; medication-related costs; and negative perceptions of the PZQ drug.

CONCLUSIONS

Availability and accessibility of PZQ seem to be a big challenge. PZQ uptake is further hampered by health systems and community-related and socio-cultural factors. Thus there is a need to bring schistosomiasis drug treatment and services closer to endemic communities, stock nearby facilities with PZQ and encourage endemic communities to take the drug. Contextualised awareness-raising campaigns are needed to debunk myths and misconceptions surrounding the drug.

Associations of water contact frequency, duration, and activities with schistosome infection risk: A systematic review and meta-analysis

BACKGROUND

Schistosomiasis is a water-borne parasitic disease which affects over 230 million people globally. The relationship between contact with open freshwater bodies and the likelihood of schistosome infection remains poorly quantified despite its importance for understanding transmission and parametrising transmission models.

METHODS

We conducted a systematic review to estimate the average effect of water contact duration, frequency, and activities on schistosome infection likelihood. We searched Embase, MEDLINE (including PubMed), Global Health, Global Index Medicus, Web of Science, and the Cochrane Central Register of Controlled Trials from inception until May 13, 2022. Observational and interventional studies reporting odds ratios (OR), hazard ratios (HR), or sufficient information to reconstruct effect sizes on individual-level associations between water contact and infection with any Schistosoma species were eligible for inclusion. Random-effects meta-analysis with inverse variance weighting was used to calculate pooled ORs and 95% confidence intervals (CIs).

RESULTS

We screened 1,411 studies and included 101 studies which represented 192,691 participants across Africa, Asia, and South America. Included studies mostly reported on water contact activities (69%; 70/101) and having any water contact (33%; 33/101). Ninety-six percent of studies (97/101) used surveys to measure exposure. A meta-analysis of 33 studies showed that individuals with water contact were 3.14 times more likely to be infected (OR 3.14; 95% CI: 2.08-4.75) when compared to individuals with no water contact. Subgroup analyses showed that the positive association of water contact with infection was significantly weaker in children compared to studies which included adults and children (OR 1.67; 95% CI: 1.04-2.69 vs. OR 4.24; 95% CI: 2.59-6.97). An association of water contact with infection was only found in communities with ≥10% schistosome prevalence. Overall heterogeneity was substantial (I2 = 93%) and remained high across all subgroups, except in direct observation studies (I2 range = 44%-98%). We did not find that occupational water contact such as fishing and agriculture (OR 2.57; 95% CI: 1.89-3.51) conferred a significantly higher risk of schistosome infection compared to recreational water contact (OR 2.13; 95% CI: 1.75-2.60) or domestic water contact (OR 1.91; 95% CI: 1.47-2.48). Higher duration or frequency of water contact did not significantly modify infection likelihood. Study quality across analyses was largely moderate or poor.

CONCLUSIONS

Any current water contact was robustly associated with schistosome infection status, and this relationship held across adults and children, and schistosomiasis-endemic areas with prevalence greater than 10%. Substantial gaps remain in published studies for understanding interactions of water contact with age and gender, and the influence of these interactions for infection likelihood. As such, more empirical studies are needed to accurately parametrise exposure in transmission models. Our results imply the need for population-wide treatment and prevention strategies in endemic settings as exposure within these communities was not confined to currently prioritised high-risk groups such as fishing populations.

The impact of HIV infection on clinical presentation and mortality among persons with hepatocellular carcinoma in Kampala, Uganda

BACKGROUND

HIV infection is associated with more rapid progression of some comorbidities. This study assessed the impact of HIV-infection on the presentation and outcome of HCC.

METHODS

HCC patients attending the Mulago National Referral Hospital in Uganda were enrolled into a natural history study of HCC between March 2015 and February 2019. Standardized methods were used to collect clinical, ultrasound and laboratory data at enrolment. HCC cases were confirmed and enrolled based on a combination of clinical, ultrasound, tumor marker and pathology data. Follow-up contact was made at one, three, six, and twelve months post-enrolment to determine vital status. Symptoms and signs at diagnosis and subsequent survival were compared by HIV status. Kaplan Meier curves were used to assess HCC survival.

RESULTS

Of 441 persons with HCC, 383 (87.0%) died within 12 months following HCC diagnosis. The median (IQR) survival was 42 (20, 106) days. HIV infection was present in 79 (18%) cases. After adjusting for baseline demographic and clinical characteristics, HIV infection was associated with increased mortality but only among those with severe HIV-associated immunosuppression (CD4 count < 200 cells per cubic milliliter), aHR (95% C) = 2.12 (1.23-3.53), p = 0.004, and not among PLWH with ≥ 200 CD4 cells per cubic milliliter, aHR (95% C) = 1.15 (0.82-1.60), p = 0.417.

CONCLUSION

Among relatively young Ugandans, HCC is a devastating disease with rapid mortality that is especially rapid among people living with HIV(PLWH). HIV was associated with slightly higher mortality, notably among PLWH with lower CD4 cell counts. As a substantial majority of PLWH diagnosed with HCC were engaged in HIV care, further investigation should determine the effectiveness of incorporating screening and early identification of HCC among high-risk individuals into existing HIV care programs. Concurrent with growing access to curative localized treatment for HCC in sub-Saharan Africa, leveraging HIV care infrastructure affords opportunities for earlier HCC intervention.

UCP-LF and other assay methods for schistosome circulating anodic antigen between 1978 and 2022

Detection of circulating anodic antigen (CAA) is known for its high sensitivity in diagnosing schistosomiasis infection, even in low-prevalence settings. The Up-Converting Phosphor-Lateral Flow (UCP-LF) assay developed in 2008 presented greater sensitivity than other assay methods in use for CAA detection. Our study aims to comprehensively review all studies conducted in this area and thus generate informed conclusions on the potential for adopting the UCP-LF assay for diagnosing this important yet neglected tropical disease. Using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, we generated search criteria to capture all studies in English journals available in the Scopus and PubMed databases on 20 December 2022. A total of 219 articles were identified, and 84 that met the inclusion criteria were retrieved and eventually included in the study. Twelve different assay methods were identified with a noteworthy transition from enzyme-linked immunosorbent assay (ELISA) to the UCP-LF assay, a laboratory-based assay that may be applicable as a point-of-care (POC) diagnostic test for schistosomiasis. Reducing the time, cost, and dependence on specialized laboratory skills and equipment, especially relating to the trichloroacetic acid extraction step and centrifugation in the UCP-LF CAA assay may go a long way to aid its potential as a POC tool. We also propose the development of a CAA-specific aptamer (short protein/antigen-binding oligonucleotide) as a possible alternative to monoclonal antibodies in the assay. UCP-LF has great potential for POC application.

Understanding perceptions of schistosomiasis and its control among highly endemic lakeshore communities in Mayuge, Uganda

BACKGROUND

Schistosomiasis is a neglected tropical disease and a serious global-health problem with over 230 million people requiring treatment, of which the majority live in Africa. In Uganda, over 4 million people are infected. Extensive parasitological data exist on infection prevalence, intensities and the impact of repeated praziquantel mass drug administration (MDA). However, how perceptions of schistosomiasis shape prevention and treatment practices and their implications for control measures are much less well understood.

METHODS

Rapid ethnographic appraisals were performed for six weeks in each of three Schistosoma mansoni high endemicity communities on the shores of Lake Victoria, Mayuge District, Uganda. Data were collected between September 2017 and April 2018. Data were collected through structured observations, transect walks, and participant observation, and sixty in-depth interviews and 19 focus group discussions with purposively recruited participants. Data were analyzed thematically using iterative categorization, looking at five key areas: perceptions of 1) the symptoms of schistosomiasis; 2) the treatment of schistosomiasis; 3) how schistosomiasis is contracted; 4) how schistosomiasis is transmitted onwards and responsibilities associated with this; and 5) how people can prevent infection and/or onward transmission.

RESULTS

Observations revealed open defecation is a common practice in all communities, low latrine coverage compared to the population, and all communities largely depend on lake water and contact it on a daily basis. Perceptions that a swollen stomach was a sign/symptom of 'ekidada' (caused by witchcraft) resulted in some people rejecting free praziquantel in favour of herbal treatment from traditional healers at a fee. Others rejected praziquantel because of its perceived side effects. People who perceived that schistosomiasis is caught from drinking unboiled lake water did not seek to minimize skin contact with infected water sources. Community members had varied perceptions about how one can catch and transmit schistosomiasis and these perceptions affect prevention and treatment practices. Open defecation and urinating in the lake were considered the main route of transmission, all communities attributed blame for transmission to the fishermen which was acknowledged by some fishermen. And, lastly, schistosomiasis was considered hard to prevent due to lack of access to safe water.

CONCLUSION

Despite over 15 years of MDA and associated education, common misconceptions surrounding schistosomiasis exist. Perceptions people have about schistosomiasis profoundly shape not only prevention but also treatment practices, greatly reducing intervention uptake. Therefore, we advocate for a contextualized health education programme, alongside MDA, implementation of improved access to safe-water and sanitation and continued research.

Prevalence of Schistosoma mansoni infection among fishermen in Busega district, Tanzania

BACKGROUND

Schistosoma (S.) mansoni infection is endemic in all regions around Lake Victoria and affects all age groups to different degrees. In most endemic areas, less attention has been paid to determining the prevalence of infection, sanitation status, and knowledge about intestinal schistosomiasis (KIS) in fishermen. Therefore, the purpose of this study was to establish the prevalence of S. mansoni infection and associated factors among fishermen in the Busega district.

MATERIALS AND METHODS

A cross-sectional study was conducted among fishermen in July, 2020 in five fishing villages in the Busega district located along Lake Victoria. A total of 352 fishermen were interviewed with regard to their sanitation status and level of KIS. A single stool sample from fishermen was examined for S.mansoni eggs by using the Formalin-Ether Concentration technique. The potential factors associated with S. mansoni infection were explored using multivariable logistic regression.

RESULTS

The prevalence of S. mansoni infection was high (65.0%) among fishermen and varied with age, whereby fishermen aged ≤36 years had the highest prevalence. Fishermen had a low level of KIS and the majority of them reported practicing open defecation during fishing (81%). These fishermen with a low level of KIS and who reported defecating in open areas during fishing had 2.8 times (95% CI: 1.0-7.2) and 2.1 times (95% CI: 1.1-3.9) higher odds of being infected with S. mansoni than those with a high level of KIS and those who did not report defecating in open areas during fishing, respectively.

CONCLUSION

S. mansoni infection was high among fishermen in the Busega district. Furthermore, fishermen had a low level of KIS and were reported to have defecated in open areas during fishing. Infection with S. mansoni was associated with age, a low level of KIS and open defecation behaviour during fishing. Therefore, mass drug administration (MDA) with praziquantel, health education, and sanitation behaviour change interventions were needed.

Behaviour Insight Shadowing: examining daily life settings for the prevention of neglected tropical disease

Background

Adaptation of daily behaviours can play a significant role in disease prevention. Behaviour Insight Shadowing (BIS) is a novel qualitative methodology, designed and used for the first time in this study, which applies the Behaviour Settings Theory as a framework for interrogating daily life patterns and identifying optimal opportunities for behaviour change.

Methods

Nine participant households were shadowed for a day, in Nigeria, the Democratic Republic of Congo and Guinea Bissau. Shadowing involved close ethnographic observation alongside integrated interviewing techniques, and then followed up with a semistructured cross-examination at the end of the observation period. Real-time insights about the attitudes and behaviours of households at high risk of neglected tropical diseases (NTDs) were then categorised by context and analysed thematically. Themes were then applied to a framework of understanding specific to NTD behaviour change and therefore informing more effective social behaviour change communications (SBCC) design. The methodology is adaptable, simple to replicate and produces in-depth, qualitative ethnographic stories.

Results

Findings highlighted important spatial and temporal aspects of target behaviours, with key differences between private and group activities. Ethnographic stories illustrated hierarchies between economic, social and temporal drivers of behaviour, and highlighted the ways in which health messages were introduced and responded to within and between households. This provided cultural levers for more impactful SBCC interventions that could tie into existing norms.

Conclusions

BIS methodology, as an adaptive ethnographic approach, provides valuable insights that enhance the findings from surveys and focus groups, specifically in the context of NTD prevention. Contextual categorisation of relevant daily behaviours is key to developing culturally appropriate SBCC and in determining whether such intervention needs to be in alignment with everyday routines and attitudes, or in disruption of them.

High prevalence of Schistosoma mansoni infection and stunting among school age children in communities along the Albert-Nile, Northern Uganda: A cross sectional study

BACKGROUND

Knowing the prevalence of schistosomiasis is key to informing programmes to control and eliminate the disease as a public health problem. It is also important to understand the impact of infection on child growth and development in order to allocate appropriate resources and effort to the control of the disease.

METHODS

We conducted a survey to estimate the prevalence of schistosomiasis among school aged children in villages along the Albert-Nile shore line in the district of Pakwach, North Western Uganda. A total of 914 children aged between 10-15 years were screened for Schistosoma mansoni using the POC-CCA and Kato Katz (KK) techniques. The infection intensities were assessed by POC-CCA and KK as well as CAA tests. The KK intensities were also correlated with POC-CCA and with CAA intensity. Anthropometric measurements were also taken and multivariate analysis was carried out to investigate their association with infection status.

RESULTS

The prevalence of schistosomiasis using the POC-CCA diagnostic test was estimated at 85% (95% CI: 83-87), being highest amongst children living closer to the Albert-Nile shoreline. Visual scoring of the POC-CCA results was more sensitive than the Kato Katz test and was positively correlated with the quantified infection intensities by the CAA test. The majority of the children were underweight (BMI<18.5), and most notably, boys had significantly lower height for age (stunting) than girls in the same age range (p < 0.0001), but this was not directly associated with S. mansoni infection.

CONCLUSION

High prevalence of S. mansoni infection in the region calls for more frequent mass drug administration with praziquantel. We observed high levels of stunting which was not associated with schistosomiasis. There is a need for improved nutrition among the children in the area.

Stakeholders' Knowledge, Attitude, and Perceptions on the Control of Taenia solium in Kamuli and Hoima Districts, Uganda

Taenia (T.) solium is a zoonotic parasite causing three diseases: Taeniasis and cysticercosis in humans and porcine cysticercosis in pigs. Although biomedically, the transmission of the parasite can be easily interrupted at six points along the life cycle, the contextual factors that may influence the adoption of these control strategies in Uganda remain unclear. This study assessed the stakeholders' knowledge, attitudes, and perceptions relating to the six control strategies for T. solium infections in Kamuli and Hoima districts, Uganda. A total of 22 focus group discussions (FGD) were conducted with pig farmers, community leaders, pig/pork traders, animal health assistants, and human health assistants. In addition, nine key informant interviews were held with senior officials in the ministries of agriculture and health and other relevant agencies at the district level. The results showed differential, limited, and fragmented knowledge on T. solium infections among stakeholders. Pig farmers, community leaders, and pig/pork traders had almost no knowledge and were often confused regarding the differences existing between T. solium and other gastro-intestinal infections in pigs and humans. Pig confinement, pit latrine construction, coverage, maintenance, and sustained use are influenced by cultural, socio-economic, and physical/ environmental factors of the study population and area. Proper sensitisation programmes and health education interventions should target all, but with appropriately focused material to suit the different stakeholder categories. Reminders or nudges may be needed to ensure that increase in knowledge translates to changes in practise. Intervention programmes should also aim to overcome challenges created by the various contextual factors operating in the specific endemic areas.

The status of schistosomiasis japonica control in the Philippines: The need for an integrated approach to address a multidimensional problem

Schistosomiasis japonica remains a public health concern in many areas of the Philippines. Adequate and updated information is essential to enhance policy and service delivery toward control and elimination. Despite the efforts on schistosomiasis control in the Philippines, some challenges remain in these dimensions. An integrated surveillance system is recommended to determine the prevalence of infection in humans, animal reservoirs, and snail intermediate hosts, allowing the identification of high-priority areas for targeted interventions. This will entail the enhancement of laboratory diagnosis capacity through the use of more sensitive techniques, complemented by capacity building of concerned human and animal health professionals. Given the zoonotic nature of schistosomiasis japonica, adopting the One Health approach is essential to influence policies and interventions that may accelerate control and elimination. This can be achieved through the attainment of mass drug administration coverage targets and intensified case finding and management, robust implementation and integration of veterinary public health activities, the conduct of snail control measures, provision of safe water, sanitation, and hygiene services, and health promotion and education into the national schistosomiasis control and elimination program. This review aimed to describe the status of schistosomiasis japonica control in the Philippines in the context of human health, animal health, vector ecology and management, environmental health, and sociocultural dimensions.

Epidemiology of Schistosoma mansoni infection in Ituri Province, north-eastern Democratic Republic of the Congo

BACKGROUND

Schistosomiasis, caused by Schistosoma mansoni, is of great significance to public health in sub-Saharan Africa. In the Democratic Republic of Congo (DRC), information on the burden of S. mansoni infection is scarce, which hinders the implementation of adequate control measures. We assessed the geographical distribution of S. mansoni infection across Ituri province in north-eastern DRC and determined the prevailing risk factors.

METHODS/PRINCIPAL FINDINGS

Two province-wide, community-based studies were conducted. In 2016, a geographical distribution study was carried out in 46 randomly selected villages across Ituri. In 2017, an in-depth study was conducted in 12 purposively-selected villages, across the province. Households were randomly selected, and members were enrolled. In 2016, one stool sample was collected per participant, while in 2017, several samples were collected per participant. S. mansoni eggs were detected using the Kato-Katz technique. In 2017, a point-of-care circulating cathodic S. mansoni antigen (POC-CCA) urine test was the second used diagnostic approach. Household and individual questionnaires were used to collect data on demographic, socioeconomic, environmental, behavioural and knowledge risk factors. Of the 2,131 participants in 2016, 40.0% were positive of S. mansoni infection. Infection prevalence in the villages ranged from 0 to 90.2%. Of the 707 participants in 2017, 73.1% were tested positive for S. mansoni. Prevalence ranged from 52.8 to 95.0% across the health districts visited. Infection prevalence increased from north to south and from west to east. Exposure to the waters of Lake Albert and the villages' altitude above sea level were associated with the distribution. Infection prevalence and intensity peaked in the age groups between 10 and 29 years. Preschool children were highly infected (62.3%). Key risk factors were poor housing structure (odds ratio [OR] 2.1, 95% 95% confidence interval [CI] 1.02-4.35), close proximity to water bodies (OR 1.72, 95% CI 1.1-2.49), long-term residence in a community (OR 1.41, 95% CI 1.11-1.79), lack of latrine in the household (OR 2.00, 95% CI 1.11-3.60), and swimming (OR 2.53, 95% CI 1.20-5.32) and washing (OR 1.75, 95% CI 1.10-2.78) in local water bodies.

CONCLUSIONS/SIGNIFICANCE

Our results show that S. mansoni is highly endemic and a major health concern in Ituri province, DRC. Infection prevalence and intensity, and the prevailing socioeconomic, environmental, and behavioural risk factors in Ituri reflect intense exposure and alarming transmission rates. A robust plan of action is urgently needed in the province.

Prevalence of Schistosoma mansoni infection among children in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Schistosomiasis is a neglected tropical disease caused by mainly Schistosoma mansoni and Schistosoma hematobium. The disease is very common in Africa including Ethiopia. Schistosoma mansoni is a major public health problem in Ethiopia especially among children. This review is aimed to indicate the prevalence of Schistosoma mansoni among children at the national and regional levels.

METHODS AND MATERIAL

The PRISMA guidelines were followed. An electronic search of PubMed, Google Scholar, Web of Science, Scopus, MEDLINE, and Google search were carried out using key terms. Articles published from the proceeding of professional associations such as the Ethiopian medical laboratory association, the Ethiopian public health association, and annual national research conferences were also searched to find additional eligible studies. Data were extracted independently by two investigators, and cross-checked by a third reviewer. The quality of included studies was assessed using JBI quality assessment criteria. Data were extracted using Microsoft excel and finally analyzed using STATA version 12. The pooled prevalence was done using a random-effects model.

RESULT

Overall 49 studies involving 20,493 children (10,572 male and 9, 921 females) were included in this meta-analysis. The pooled prevalence of Schistosoma mansoni infection was 37.13% (95%CI:30.02-44.24). High heterogeneity was observed with I2 of 99.4%, P < 0.000. According to subgroup analysis, the pooled prevalence was high in the SNNPR (41.49%: 95%CI: 19.52-63.46) followed by the Amhara region (41.11%: 95%CI: 30.41-51.8), the Tigray region (31.40%: 95%CI:11.72-51.09), and the Oromia region (28.98%: 95%CI: 18.85-39.1). Year from 2011 to 2015 contributed to the highest prevalence of Schistosoma mansoni infection among children (46.31%: 95%:34.21-59.05).

CONCLUSION

This study revealed a 37.13% prevalence of Schistosoma mansoni infection among children. This is an alert to improve and implement appropriate control strategies such as mass drug administration in Ethiopia.

Regression of Schistosoma mansoni associated morbidity among Ugandan preschool children following praziquantel treatment: A randomised trial

Preschool children suffer from morbidity attributable to Schistosoma mansoni. We compared a single and double dose of praziquantel treatment on the regression of S. mansoni associated morbidity in children less than six years in Uganda. We measured the sizes of spleen and liver as well as liver fibrosis before treatment and 8 months after treatment among children who either received one dose (n = 201) or two doses (n = 184) of praziquantel (standard oral dose of 40 mg/kg body weight). Heamoglobin measurements were also taken. Overall, liver enlargement reduced from 52.2% (95% CI (Confidence interval) 45.1, 59.3) to 17.9% (95% CI 12.9, 23.9) with a single dose and from 48.4 (95% CI 40.9, 55.8) to 17.9% (95% CI 12.7, 24.3) with a double dose and there was no significant difference between the changes in proportion of children with enlarged liver between the two treatment groups. The proportion of children with enlarged spleen was not significantly reduced in the group treated with either one or two doses, 47.8% (95% CI 41.7, 54.9) to 45.3% (95% CI 38.3, 52.4) and 48.4% (95% CI 40.9,55.8) to 40.8% 95% CI 33.6, 48.2), respectively. Liver fibrosis detected among children getting single dose (n = 9) or double doses (n = 13) resolved after treatment with praziquantel. The number of children with low heamoglobin significantly reduced from 51.2% (95% CI 44.1, 58.3) to 0.5% (0.2, 0.8) and 61.4% (95% CI 53.9,68.5) to 1.1% (95% CI 0.1, 3.9) after single and double dose treatment, respectively. These results suggest that there is no evidence of a difference in effect between one dose of praziquantel and two doses in reversing morbidity attributable to S. mansoni among children less than six years of age.

Osteopontin and malaria: no direct effect on parasite growth, but correlation with P. falciparum-specific B cells and BAFF in a malaria endemic area

Background

The dysregulation of B cell activation is prevalent during naturally acquired immunity against malaria. Osteopontin (OPN), a protein produced by various cells including B cells, is a phosphorylated glycoprotein that participates in immune regulation and has been suggested to be involved in the immune response against malaria. Here we studied the longitudinal concentrations of OPN in infants and their mothers living in Uganda, and how OPN concentrations correlated with B cell subsets specific for P. falciparum and B cell activating factor (BAFF). We also investigated the direct effect of OPN on P. falciparum in vitro.

Results

The OPN concentration was higher in the infants compared to the mothers, and OPN concentration in infants decreased from birth until 9 months. OPN concentration in infants during 9 months were independent of OPN concentrations in corresponding mothers. OPN concentrations in infants were inversely correlated with total atypical memory B cells (MBCs) as well as P. falciparum-specific atypical MBCs. There was a positive correlation between OPN and BAFF concentrations in both mothers and infants. When OPN was added to P. falciparum cultured in vitro, parasitemia was unaffected regardless of OPN concentration.

Conclusions

The concentrations of OPN in infants were higher and independent of the OPN concentrations in corresponding mothers. In vitro, OPN does not have a direct effect on P. falciparum growth. Our correlation analysis results suggest that OPN could have a role in the B cell immune response and acquisition of natural immunity against malaria.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12866-021-02368-y.

Schistosoma mansoni infection risk for school-aged children clusters within households and is modified by distance to freshwater bodies

BACKGROUND

The interaction of socio-demographic and ecological factors with Schistosoma mansoni (S. mansoni) infection risk by age and the household clustering of infections between individuals are poorly understood.

METHODS

This study examined 1,832 individuals aged 5-90 years across 916 households in Mayuge District, Uganda. S. mansoni infection status and intensity were measured using Kato-Katz microscopy. Socio-demographic and ecological factors were examined as predictors of infection status and intensity using logistic and negative binomial regression models, respectively, with standard errors clustered by household. A subgroup analysis of children was conducted to examine the correlation of infection status between children and their caretakers.

FINDINGS

Infection varied within age groups based on the distance to Lake Victoria. Children aged 9-17 years and young adults aged 18-29 years who lived ≤0.50km from Lake Victoria were more likely to be infected compared to individuals of the same age who lived further away from the lake. Infections clustered within households. Children whose caretakers were heavily infected were 2.67 times more likely to be infected.

CONCLUSION

These findings demonstrate the focality of schistosome transmission and its dependence on socio-demographic, ecological and household factors. Future research should investigate the sampling of households within communities as a means of progressing towards precision mapping of S. mansoni infections.

Hepatic schistosomiasis, upper gastrointestinal bleeding, and health related quality of life measurements from the Albert Nile Basin

BACKGROUND

Health related quality of life measurements are vital elements of public health surveillance that uncover unmet health needs and predict the success of health interventions. We described health related quality of life measurements using the EuroQoL 5-dimension (EQ-VAS/EQ-5D) instrument and associated factors among patients with upper gastrointestinal bleeding (UGIB) and hepatic schistosomiasis at a rural health facility in the Albert Nile Basin, Uganda.

METHODS AND MATERIALS

This was a cross-sectional study at Pakwach Health Centre IV. Participants included adult inpatients and outpatients with a history of UGIB and ultrasound evidence of hepatic schistosomiasis. We evaluated and recorded each participant's medical history, physical examination, laboratory tests results, ultrasound results, and endoscopy findings. We also recorded health related quality of life measurements using the EuroQoL 5-dimension instrument and derived disability weights from EQ-VAS and EQ-5D measurements. These were our dependent variables. Descriptive and inferential statistics were generated summarizing our findings.

RESULTS

We found 103 participants had a history of upper gastrointestinal bleeding and hepatosplenic schistosomiasis. Sixty percent were between the ages of 30-49 years, 59% were females, 74% were farmers, 92% had splenomegaly, 88% had varices at endoscopy, 22% were medical emergencies with acute variceal upper gastrointestinal bleeding, and 62% had anemia. Measures of the different dimensions of health from 101 participants with patient reported outcomes revealed 77 (76%) participants experienced problems in self-care, 89 (88%) participants reported anxiety or depression, and 89 (88%) participants experienced pain or discomfort. The median EQ-VAS derived disability weights and median EQ-5D index-derived disability weights were 0.3 and 0.34, respectively. Acute upper gastrointestinal bleeding, praziquantel drug treatment, and age by decade predicted higher EQ-VAS derived disability weights (p value < 0.05). Under weight (Body mass index ≤ 18.5), acute upper gastrointestinal bleeding, ascites, age by decade, female gender, and praziquantel drug treatment predicted higher EQ-5D index- derived disability weights (p value < 0.05).

CONCLUSION

Adult patients with upper gastrointestinal bleeding and hepatic schistosomiasis from this primary health facility experience poor health and considerable health loss. Several factors predicted increased health loss. These factors probably represent key areas of health intervention towards mitigating increased health loss in this population.

Schistosomiasis messaging in endemic communities: Lessons and implications for interventions from rural Uganda, a rapid ethnographic assessment study

Background

Over 240 million people are infected with schistosomiasis, the majority in sub-Saharan Africa. In Uganda, high infection rates exist in communities on the shores of Lake Victoria. Praziquantel mass drug administration (MDA) delivered by village health teams is the mainstay of schistosomiasis control. However, treatment uptake remains suboptimal, with many people unaware of treatment or thinking it is only for children. Furthermore, people are often rapidly reinfected post-treatment due to continued exposure. In three Schistosoma mansoni high endemicity lake-shore communities in Mayuge district, Eastern Uganda, we investigated the sources of schistosomiasis information, remembered content of information, and the perception of information and related practices towards the control of schistosomiasis.

Methods and principal findings

Data were collected from September 2017 to March 2018 using a rapid ethnographic assessment that included transect walks, observations, individual in-depth interviews and focus group discussions. Data were analysed thematically using iterative categorisation. We found that the main sources of schistosomiasis information included health workers at government facilities, village health teams, teachers, and radio programmes produced by the Ministry of Health. These messages described the symptoms of schistosomiasis, but did not mention the side effects of praziquantel treatment. Despite this messaging, the main cause of the disease and transmission was unclear to most participants. The translation of schistosomiasis on the radio into the local language ‘ekidada’—meaning swollen stomach—increased, rather than reduced, confusion about the cause(s) of schistosomiasis, due to believed links between ekidada and witchcraft, and prompted a reluctance to engage with treatment or preventative efforts.

Conclusion and significance

This study highlights gaps in schistosomiasis messaging. We recommend MDA is complemented by effective, evidence-based messaging on schistosomiasis transmission, prevention, and treatment, that is sensitive to local language and context issues, resulting in clear, concise, and consistent messages, to increase effectiveness.

Schistosomiasis is a global-health concern causing severe disease, particularly in communities in tropical areas such as Uganda. The parasite is spread in areas with inadequate sanitation and a lack of a safe water supply. Government control efforts focus on mass drug administration for people living in affected areas, with most treatments administered to school-aged children. However, drug uptake is low, and people are rapidly reinfected. In three heavily affected communities on the shores of Lake Victoria, we explored the sources of schistosomiasis information, how messages were relayed to community members, the remembered content of these messages and the way messages were perceived. Common sources of information were health workers at government health facilities, trained village health team members, teachers, and radio programmes. Our findings show that the information shared from the different sources is not consistent and, in some cases, this has caused confusion and prompted a reluctance to engage with treatment or preventative efforts. We propose a framework where there is dialogue between community member representatives, health workers based in the community, and government technical staff to come up with clear, concise, and consistent messages.

Associations of IL13 gene polymorphisms and immune factors with Schistosoma haematobium infection in schoolchildren in four schistosomiasis-endemic communities in Ghana

BACKGROUND

Schistosomiasis remains a major public health issue with over 90% of the prevalence rates recorded in Sub-Saharan Africa. In this study, the relationships between different interleukin gene polymorphisms (IL-13-591A/G, IL-13-1055C/T, IL-13-1258A/G) and Schistosoma haematobium infection levels were evaluated; as well as the host plasma antibodies and cytokine profiles associated with schistosomiasis infection.

METHODOLOGY

A total of 469 school children aged 6 to 19 years from four schistosomiasis-endemic communities in Ghana were involved. Single urine and stool samples were obtained from each pupil, processed via sedimentation and Kato-Katz, and examined via microscopy for Schistosoma and soil-transmitted helminth (STH) eggs. Next, venous blood samples were drawn from 350 healthy pupils, and used to measure antibody and plasma cytokine levels by ELISA. Single nucleotide polymorphisms in the IL-13 gene were genotyped on 71 selected blood samples using the Mass Array technique.

PRINCIPAL FINDINGS AND CONCLUSION

The overall prevalence of urinary schistosomiasis was 21.11%. Community-level prevalences were 17.12%, 32.11%, 20.80%, and 15.32% for Asempaneye, Barikumah, Eyan Akotoguah, and Apewosika respectively. Generally, higher S. haematobium infection prevalence and intensity were recorded for participants with genotypes bearing the IL13-1055C allele, the IL13-591A, and the IL13-1258A alleles. Also, higher S. haematobium infection prevalence was observed among participants in the 12-14-year age group with the IL13-1055C, IL13-591A, and IL13-1258A alleles. Interestingly, higher STH prevalence was also observed among participants with the IL13-1055C, IL13-591A, and IL13-1258A alleles. Furthermore, the age-associated trends of measured antibodies and cytokines of S. haematobium-infected school-children depicted a more pro-inflammatory immune profile for pupils aged up to 1l years, and an increasingly anti-inflammatory profile for pupils aged 12 years and above. This work provides insight into the influence of IL-13 gene polymorphisms on S. haematobium, and STH infections, in school-aged children (SAC).

Praziquantel and Upper Gastrointestinal Bleeding in Hepatic Schistosomiasis: A Quasi-Experimental Study

Background

There is a general consensus that widespread use of praziquantel in populations where schistosomiasis is endemic prevents development of hepatic schistosomiasis and its complications. However, a few studies have reported discordant findings linking praziquantel to the occurrence of upper gastrointestinal bleeding (UGIB) in some patients with hepatic schistosomiasis and varices.

Objective

We explored if there was any causal association between recent praziquantel use (rPZQ) and upper gastrointestinal bleeding in hepatic schistosomiasis in rural Africa.

Patients and Methods

A quasi-experimental, retrospective case-controlled study was performed. It involved adult patients with past or acute UGIB, varices, periportal fibrosis, and/or cirrhosis. Cases had acute variceal bleeding while controls did not. The outcome was the frequency of lifetime episodes of UGIB and exposure was rPZQ (received praziquantel in the last 11 months from the date of enrollment). The data analysis included 2 × 2 tables, logistic regression, and propensity-score matching. Odds ratios (ORs), average treatment effects (ATEs), and their 95% confidence intervals (CIs) were used for inference.

Results

Over 6 weeks, we enrolled 19 cases with 92 lifetime episodes of UGIB, and 66 controls with 192 lifetime episodes of UGIB. Cases were more likely to experience UGIB than controls following rPZQ (92% vs. 62%; OR 7.6; 95% CI 3.4–17). Factors predictive of more lifetime episodes of UGIB at multivariable analysis included rPZQ (adjusted OR 13; 95% CI 2.9–53), relative leukocytosis (adjusted OR 26; 95% CI 7.6–89), large varices (adjusted OR 5.0; 95% CI 1.7–15), a family member with hepatosplenic schistosomiasis (adjusted OR 19; 95% CI 7.4–51), advanced periportal fibrosis (adjusted OR 8.0; 95% CI 2.6–22), ascites (adjusted OR 14; 95% CI 4.3–47), and jaundice (adjusted OR 32; 95% CI 7.8–128). While the ATE following rPZQ among the treated was 0.40 (95% CI 0.33–0.48).

Conclusions

Our findings suggest the presence of a plausible causal association between recent praziquantel use and increased frequency of UGIB in our study population.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-020-00222-7.

Bladder Cancer and Associated Risk Factors: The African Panorama

The African continent is unique in terms of its epidemiological evidence, causes, and possible future trends for bladder cancer (BCa). Factors include smoking rates and parasitic infection with Schistosoma haematobium. These issues in Africa could be addressed by increasing cultural awareness of BCa causes and symptoms via social media, banning smoking in public places, and ensuring that praziquantel is readily available in areas at high risk of schistosomiasis.

Open defecation-free slippage and its associated factors in Ethiopia: a systematic review

BACKGROUND

Recent studies have shown an increase in open defecation and slippage of open defecation-free certified villages in Ethiopia, despite significant progress the country made on sanitation programs. Hence, realizing of existing facts, this study was conducted aiming at a critical review of available literature and to provide consolidated data showing the level of slippage and its associated factors in Ethiopia.

METHODS

Systematic literature searches were performed from four international databases. The search involved articles published from December 1, 2013, up to June 4, 2019. The Cochran's Q and I² test statistics were used to check heterogeneity among the studies. To negotiate heterogeneity from qualitative data, we used a mixed-method approach. The researchers also conducted a publication bias assessment and sensitivity analysis. A random effect meta-analysis was employed to determine the pooled estimates of open defecation free slippage rate with a 95% confidence interval (CI). The data analysis was performed using the CMA V.3 software program.

RESULT

After screening 1382 studies, 12 studies were finally included in this systematic review. The estimated pooled rate of open defecation-free slippage in Ethiopia was 15.9% (95% CI 12.9-19.4%). The main contributing factors for open defecation-free slippage were lack of technical support, financial constraints, low-quality building materials, improper program implementation, and lack of sanitation marketing.

CONCLUSION

It was estimated that 1 out of 6 Ethiopian households engaged in open defecation after they have certified open defecation-free status, implying the low possibility of achieving sustainable development goals of 2030, which aims to ensure sanitation for all. Therefore, the government of Ethiopia and donors should better give special attention to the following options: (1) awareness for open defecation-free slippage, (2) launch a post-open defecation-free program, and (3) encourage research on pro-poor sustainable sanitation technologies.

Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response

Schistosomiasis is one of the most common parasitic diseases in the world, and most infected people (90%) live in Africa. Global control efforts use measures of population-level transmission to target programs and assess progress toward elimination. Monitoring Schistosoma mansoni transmission has traditionally relied on examining stool with microscopy, which is difficult to scale in large programs and has low sensitivity as infection burdens decline. Our results show that antibody-based measures of transmission align well with stool-based measures, provide higher sensitivity at lower levels of transmission, and enable fine-scale estimates of force of infection by geography and age. The findings represent a major step toward use of serosurveillance to guide schistosomiasis control efforts in Africa.

Schistosomiasis is among the most common parasitic diseases in the world, with over 142 million people infected in low- and middle-income countries. Measuring population-level transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected using stool microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to S. mansoni soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. We estimated force of infection among children using the seroconversion rate and examined how it varied geographically and by age. At the community level, serological measures of transmission aligned with stool-based measures of infection (ρ = 0.94), and serological measures provided more resolution for between-community differences at lower levels of infection. Force of infection showed a clear gradient of transmission with distance from Lake Victoria, with 94% of infections and 93% of seropositive children in communities <1.5 km from the lake. Force of infection increased through age 3 y, by which time 65% (95% CI: 53%, 75%) of children were SEA positive in high-transmission communities—2 y before they would be reached by school-based deworming programs. Our results show that serologic surveillance platforms represent an important opportunity to guide and monitor schistosomiasis control programs, and that in high-transmission settings preschool-age children represent a key population missed by school-based deworming programs.

Assessing the diversity and distribution of potential intermediate hosts snails for urogenital schistosomiasis: Bulinus spp. (Gastropoda: Planorbidae) of Lake Victoria

BACKGROUND

The Lake Victoria basin is one of the most persistent hotspots of schistosomiasis in Africa, the intestinal form of the disease being studied more often than the urogenital form. Most schistosomiasis studies have been directed to Schistosoma mansoni and their corresponding intermediate snail hosts of the genus Biomphalaria, while neglecting S. haematobium and their intermediate snail hosts of the genus Bulinus. In the present study, we used DNA sequences from part of the cytochrome c oxidase subunit 1 (cox1) gene and the internal transcribed spacer 2 (ITS2) region to investigate Bulinus populations obtained from a longitudinal survey in Lake Victoria and neighbouring systems during 2010-2019.

METHODS

Sequences were obtained to (i) determine specimen identities, diversity and phylogenetic positions, (ii) reconstruct phylogeographical affinities, and (iii) determine the population structure to discuss the results and their implications for the transmission and epidemiology of urogenital schistosomiasis in Lake Victoria.

RESULTS

Phylogenies, species delimitation methods (SDMs) and statistical parsimony networks revealed the presence of two main groups of Bulinus species occurring in Lake Victoria; B. truncatus/B. tropicus complex with three species (B. truncatus, B. tropicus and Bulinus sp. 1), dominating the lake proper, and a B. africanus group, prevalent in banks and marshes. Although a total of 47 cox1 haplotypes, were detected within and outside Lake Victoria, there was limited haplotype sharing (only Haplotype 6 was shared between populations from Lake Victoria open waters and neighbouring aquatic systems) - an indication that haplotypes are specific to habitats.

CONCLUSIONS

The Bulinus fauna of Lake Victoria consists of at least B. truncatus, B. tropicus, Bulinus sp. 1 (B. trigonus?) and B. ugandae. The occurrence and wide distribution of Bulinus species in Lake Victoria potentially implies the occurrence of urogenital schistosomiasis in communities living along the shores and on islands of the lake who depend solely on the lake for their livelihood. More in-depth studies are needed to obtain a better picture of the extent of the disease in the Lake Victoria basin.